Drill-chuck.



Patented Mar. 20, I900. T. J. KITTU.

DRILL CHUCK.

(Application filed Oct. 27, 1899.

(No Model.)

5] Vl U an {on T/zo mas rffio UNITED STATES PATENT OFFICE.

THOMAS J. KITTO, OF DOE RUN,MISSOURI, ASSIGNOR OF TWO-TIIIRDS TO G. O.CLEMENTS AND OTTO -LOTZ, OF SAME PLACE.

DRILL-CHUCK.

SPECIFICATION forming part of Letters Patent No. 645,854, dated March20, 1900.

Application filed October 27,1899. Serial No. 734,952. (No model.)

To all whom it may concern:

Be it known that I, THOMAS J. Krrro, a citizen of the United States,residing at Doe Run, in the county of St. Frangois and State ofMissouri, have invented a new and useful Drill- Ohuck, of which thefollowing is a specification.

This invention relates to drill-chucks; and the object in view is toprovide a simple, dura- IO ble, and efiective chuck and adapted todrills of various sizes. While the drill-chuck is illustrated as of aform especially designed for use in connection with rock-drills, it isto be understood that the chuck hereinafter described maybe used forgripping other objects than drills and may be used upon lathes andvarious other machines, such as are employed by jewelers, s'ilversmiths,miners, and

machinists in general. I

One of the main advantages of the present invention resides in having adirect grip and a uniform pressure on the drill or the shank thereof,and this pressure is distributed throughout a considerable portion ofthe drill- 2 5 shank, so that there is no liability to twist or bend theshank, and at the same time by a slight loosening of the clamping-boltthe drill will be released, and when replaced may be securely held by aslight manipulation of the tightening means.

The detailed objects and advantages of the invention will appear in' thecourse of the subjoined description.

The invention consists in a drill-chuck em 3 5 bodying certain novelfeatures and details of construction and arrangement of parts, ashereinafter fully described, illustrated in the drawings, andincorporated in the claim.

In the accompanying drawings, Figure 1 is a perspective view of adrill-chuck constructed in accordance with the present invention. Fig. 2is alongitudinal section through the same, showing the drill in place.Fig. 3 is a transverse section through the same. Fig. 4

is a face view of the chuck-body, showing the intersecting slotsor-recesses in one side thereof. Fig. 5 is a detail perspective view ofthe key looking toward the side which contains the bearing or grippingsurfaces. Fig. 6 is a similar view of the eyebolt.

' Similar numerals of reference designate corresponding parts in thedifferent figures of the drawings.

The body of the drill-chuck (indicated at 1) has a length somewhatgreater than its width, being of oblong form. The drill-body is providedwith a central longitudinal bore 2 ex tending a suitable distance intothe same, which bore is in communication with the intersectin g slots orrecesses comprising a longer branch 3, which extends longitudinally ofthe body of the chuck, and a shorter branch 4, which extendstransversely of the body and which intersects or crosses the branch 3centrally,bein'g itself centrally intersected by the branch 3.

The transverse branch 4 is deeper than the longitudinal branch orportion 3 of the recess and extends beyond the longitudinal bore 2,terminating in curved shoulders 5,which communicate with a centralopening 6, through which the shank of the eyebolt, hereinafterdescribed, passes. The longitudinal portion 3 of the recess terminatesin the longitudinal bore 2 and is of approximately the same width as thediameter of the bore 2.

v The body of the chuck is also provided with a socket 7, which extendsbeyond the end of the longitudinal portion 3 of the recess and forms, infact, a continuation of the longitu- 8o dinal bore 2, being designed toreceive the butt-end of the drill when inserted in the chuck. By reasonof the intervention of the transverse portion 4 of the recess twohearing or gripping surfaces 8 are provided on opposite sides of therecess 4, against which the shank of the drill is seated and held in amanner hereinafter described.

The key 9 is of oblong form and corresponds in shape to the portion 3 ofthereoess, which in reality constitutes a keyway. The key 9 is removablyfitted in said keyway, and its inner surface or edge comprises hearingor gripping surfaces 10, which are spaced apart by cutting away thecentral portion of the inner surface of the key, as shown at 11, the

key being cut away, as described, to prevent any pressure being broughton the drill opposite the space between the bearing-surfaces 8, above.referred to, which pressure would subject the shank of the drill to abending action. The key 9 is also provided upon its outer surface withshoulders 12, spaced apart to form between them a groove 13, which ispreferably rounded or concaved, as shown, to form a seat for theeyebolt, by means of which the key is operated.

The eyebolt 1a resembles a link of an ordinary chain, being oblong andof ellipsoidal shape. This link is of a cross-sectional shape and size,adapting it to fit within and fill the transverse portion 4 of thecruciform recess, and said bolt is provided with a threaded shank 15,which passes through the opening 6, hereinabove described, and receivesupon its projecting threaded end a tightening device 16, which forconvenience and the sake of simplicity is shown in the form of anordinary nut capable of being operated by a wrench.

In assembling the parts of the drill-chuck the key 9 is inserted throughthe eye of the. bolt, and the bolt, together with the key, then insertedin the respective portions of the intersecting slots or recesses. Thebuttend or shank of the drill is then inserted in the longitudinal boreof the drill-body and passed through the eyebolt until its butt-end isreceived in the socket 7. The nut or tightening device is then appliedto the projecting end of the shank of the eyebolt and may be tightenedeither by hand or by a wrench,which has the effect of drawing theeyebolt farther through the body of the chuck, and thereby forcing thebearing or gripping surfaces to be brought into firm engagement with thedrillshank and forcing said shank into firm engagement with thebearing-surfaces 8 of the drill-receiving bore.

By means of the construction above described it will be seen that bysimply loosening the nut or tightening device pressure on thedrill-shank is immediately relieved, thus permitting the drill to beextracted from the chuck. \Vhen the drillis reinserted, a slighttightening of the nut will eifect a firm gripping of the drill-shank,and the drill will thus be firmly secured in place.

In drills of the type above shown and described it has been customary touse in connection with a key a bolt in the form of a staple, having itsterminals threaded and passed through the chuck-body, thus necessitatingthe employment of two nuts, one for each end of the staple-bolt. Underthis construction, however, the two nuts are so close together that itis next to impossible to turn them with a wrench, and as a result minersgenerally use one of the nuts and knock the other 01f. In using a singlenut for tightening the staple the latter soon becomes twisted out ofshape and brings an indirect draft and uneven pressure on the key anddrill-shank and the chuck as a whole is soon rendered useless. Under theconstruction described in this application and by reason of theemployment of a single centrally-located nut and solid link there isalways a direct draft and uniform pressure on the shank of the drill,and as the bearingsurfaces of the key come opposite correspondingbearing-surfaces within the interior of the chuck-body there is notendency to twist or bend the drill or its shank. The chucks may ofcourse be made in any size to accommodate drills of various sizes, andwill also be found useful as a pipe-chuck. The drillchuck is neat inappearance, simple and durable in construction, and will be foundefiicient in practice.

I attach especial importance to the construction of the key-block withthe transversely-curved gripping-faces 10, which are separated by theintervening recess 11 on the inner side of the key-block. Said key-blockis fitted in the longitudinal part or branch of the intersecting slotsin such relation that the spaced grippingfaces 10 thereof will bebrought into opposing positions relatively to the cross-sectional curvedbearing-faces 8 on the inside of the bit-socket. This disposition of thekey-block with relation to the body brings the recess 11 thereof in thesame transverse plane as the bolt-aperture 6 in the body,' and thekey-block is adapted for engagement centrally with the elongated eye ofthe bolt,- the shank of which passes through the boltaperture andreceives the single nut. The key-block is thus arranged to centrallyreceive the strain or draft of the eyebolt when the nut 10 is tightened,and said key-block operates to distribute the strain uniformly inopposite directions toward its gripping-faces 10. The middle portion ofthe key-block is out of engagement with the bit or shank by reason ofthe formation of the recess 11 therein, and this bit or shank is solidlyclamped or gripped between the opposing faces 8 of the body and 10 ofthe key, whereby the bolt does not exert pressure directly on the bit orshank, and the latter is gripped or held in the chuck in a manner towholly obviate any tendency of the shank to bend by reason of thepressure of the bolt.

Having thus described the invention, what I claim, and desire to secureby Letters Patent, is-

A drill-chuck comprising a body provided in one side with intersectingslots and on the other side of its bit-socket with thecross-sectionally-curved bearing-faces, 8, separated by an intermediatebolt-aperture, a key fitted in the longitudinal slot of the body andprovided on its inner side with the cross-sectionallycurvedgripping-faces, 10,which are separated by an intervening transverseslot, 11, and are in opposing relation to the bearing-faces, 8, abit-shank fitted in the socket, a single-shank bolt having an elongatedeye arranged to span the socket and embrace the key and the bit- Intestimony that I claim the foregoing as shank, and a single nut screwedon the shank my own I have hereto affixed my signature in of theeyebolt, whereby the strain of the bolt the presence of two witnesses.

is distributed by the recessed key and the bit- THOMAS J. KITTO. shankis solidly clamped between the bearing Witnesses: and gripping facesonly of the body and the J. M. ELVINS,

key, respectively, as set forth 7 POLITTE ELVINS.

